LG MCV1306 - System Part

3-33
ELECTRICAL TROUBLESHOOTING GUIDE
Power on.
FRONT board OK.
Check FFC cable (Pin29).
Check SMPS board.
Check FFC cable.
Check MAIN board.
Check SMPS board.
Check MAIN board.
Replace DIG301.
Q301, 303, 304
grid voltage OK?
Replace LED
(LD302 ~ LD322).
Check MAIN board.
“HELO”
Display on FLD
OK?
Volume LED
(LD302~LD322)
Turn on?
When turn
the volume, count is
change?
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
CN301
cable connection
OK?
CN301 Pin18
+12 V OK?
CN301 Pin13, 14
signal OK?
CN301
Pin20, 21, 22 data signal
OK?
CN301
Pin27, 28, 29 power
OK?
CN301 Pin7, 9, 12
I2C data OK?
2. SYSTEM PART
YES
YES
YES
YES
YES
YES
YES
YES
YES